JSFiddle - React, Tailwind, and code Playground

HTML

<script>
 function sayHi() {
  alert("Hello!");
}
</script>

<form id="form1">
 <fieldset>
  <select>
   <option value="1">One</option>
   <option value="2">Two</option>
   </select>
   </fieldset>
  <div id="checks"></div>
</form>

JavaScript

var checkb = document.getElementById("checks")
checkb.innerHTML = "<input type='checkbox' id='test' name='one' onmouseover='sayHi()'>Tets One";